The present invention relates to a detent changeover switch apparatus capable of changing over click feeling generated by an operating portion of an operating switch.
Conventionally, as an input operation system for performing operation setting of various vehicle-loaded equipment such as an air conditioning device and an audio device, various kinds of operating switches are mounted on a vehicle corresponding to respective functions. As one example, with respect to the operating switches of the air conditioning device, for example, a temperature setting switch for setting a supply-air temperature, an air volume setting switch for setting an air volume, an air blow direction setting switch for setting an air blow and the like are used. As such a group of switches, a rotary operating switch, that is, a rotary switch which performs setting of various functions by rotatably operating a dial knob of a rotational operation type as an operating portion has been popularly used.
Further, this kind of rotary switch is provided with a detent mechanism capable of imparting a desired operation force or click feeling to the dial knob as a click for ensuring an operation of the dial knob by enhancing operation feeling of the dial knob. As one example of such a detent mechanism, there has been known a motor-driven click generating mechanism shown in JP-A-2006-178861 which imparts click feeling to a dial knob of a rotary switch using a motor, for example. In the disclosed technique, the motor is connected to the dial knob of the rotary switch, and upon a rotational operation of the dial knob, the motor is driven in the direction opposite to the knob operating direction thus imparting a reaction force to the dial knob and hence, an operating force is imparted to an operator as click feeling.
Recently, to realize the reduction of the number of parts of the operating switch, there has been an attempt to use one rotary switch in common among a plurality of selection functions. In this kind of operating switch having the common use structure, a switch controller which constitutes a control unit of the input operation system brings a switch determination mode into a function selection setting mode in a switch determination initial state. At this point of time, when the dial knob is operated, in response to a switch signal acquired from the rotary switch, a vehicle-loaded equipment which the operator requires setting a function thereof is selected and designated. The switch controller, after the selection and the designation of the vehicle-loaded equipment, changes over the switch determination mode to a detail setting mode. When the dial knob is operated at this point of time, in response to a switch signal acquired from the rotary switch, the detail of the selected and designated vehicle-loaded equipment is set to a state corresponding to the switch operation.
In case of the operating switch having the common-use structure, it is desirable that the click feeling generated in the rotary switch by the detent mechanism differs for every selection function. Here, when a motor-driven click generating mechanism described in JP-A-2006-178861 is used as a detent mechanism, in changing over click feeling of the dial knob based on respective selection functions, the changeover of click feeling is performed by controlling a reaction force imparted to the dial knob by a motor based on the respective selection functions. That is, when the strong click is necessary, the reaction force of the motor is increased so as to allow the dial knob to generate the strong click, while when the weak click is necessary, the reaction force of the motor is decreased so as to allow the dial knob to generate the weak click.
Further, the rotary switch of the air conditioner is, in view of setting of temperature or selection functions, often a switch which limits a rotational operation range in which the dial knob is operated within a predetermined rotational operation range. Accordingly, this type of rotary switch is configured to be rotary operated within a range of 120 degrees, 180 degrees, 270 degrees or the like, for example, corresponding to a usage of the rotary switch. Here, when the motor-driven click generating mechanism described in JP-A-2006-178861 is used as the detent mechanism, to bring the dial knob into a fixed state at a preset stop position, a reaction force larger than a reaction force generated at the time of generating click by the motor is generated thus restricting the further rotational operation of the dial knob.
However, when the motor-driven click generating mechanism is used as the detent mechanism, it is necessary to perform processing for a control of the reaction force generated by the motor for changing over the click feeling generated in the dial knob by the detent mechanism or bringing the dial knob into a fixed state. Accordingly, this type of motor control requires complicate processing and hence, when the motor-driven click generating mechanism is used as the detent mechanism, a control unit of a switch system requires a complete motor control. Accordingly, also for reducing a burden on processing of the control unit, there has been a demand for changeover and fixing of click of the rotary switch which can be performed with processing as simple as possible.